Aircraft and method for intercepting an airborne target

ABSTRACT

There is disclosed an aircraft for intercepting an airborne target, the aircraft comprising: a frame; a plurality of lines of a first type, each attached to the frame at a first end, and free at the other end; and a plurality of lines of a second, different, type, each attached to the frame at a first end, and free at the other end.

The following invention relates to an aircraft and method for intercepting an airborne target.

It is known to intercept an airborne target, for example a light unmanned rotorcraft, by firing a net towards the target. The target rotorcraft may then tend to become at least partially disabled either by interference of the net lines with the rotors, or by the attachment of the net and the associated extra mass affecting flight. However, the disabled target rotorcraft may still pose a threat due to the difficulty in controlling its landing.

According to a first aspect of the invention there is provided an aircraft for intercepting an airborne target, the aircraft comprising: a frame; a plurality of lines of a first type, each attached to the frame at a first end, and free at the other end; and a plurality of lines of a second, different, type, each attached to the frame at a first end, and free at the other end.

By providing different types of lines, more possibilities of attaching the aircraft to the target can be provided, increasing the chance of the aircraft connecting to the target. In particular, the attachment may come about from a line tangling with a rotor or propeller or other moving part of the target.

The frame may comprise: an inner member; an outer member; and interconnecting struts attaching the inner member to the outer member, the first type of lines are attached to the inner member, and the second type of lines are attached to the outer member.

The outer member may be a loop member, and the inner member is a loop member located within the outer member.

Each loop member may have the form of an annular member.

The outer member may be at least two linear members and the inner member is at least one linear member, the inner member being arranged between the at least two outer members.

Such frame features contribute to the overall provision of a consistently arranged set of lines, which can tend to provide reliability.

The first type of lines may be thinner than the second type of lines.

Each of the second type of lines may comprise: a flexible tubular member, having a wall and defining a bore; and a fluid adhesive housed within the flexible tubular member, wherein the flexible tubular member is configured to express the fluid adhesive through the wall.

The flexible tubular member may comprise: a plurality of slits through the wall, which slits are configured to remain generally closed, but on deformation of the flexible tubular member can open to permit the expression of the adhesive.

The slits may follow a portion of the circumference of the tubular member.

The wall of the tubular member may be in the form of a porous matrix such that the fluid adhesive may be urged to the outer diameter of the tubular member.

Thus there is provided a line which can tend to attach to the target by way of bonding, and thereby may attach to non-moving parts of the target, such as the housing or nacelle.

The aircraft may be a rotorcraft, may have a mass of 25 kg or less, and may be remotely or autonomously piloted.

According to a second aspect of the invention there is provided a method of intercepting an airborne target comprising: —providing an aircraft comprising: a frame; a plurality of lines of a first type, each attached to the frame; and a plurality of lines of a second type, each attached to the frame, and—flying the aircraft over and across the airborne target such that the lines may attach to the airborne target.

The method may further comprise, once the lines have attached the aircraft to the airborne target, removing the airborne target by flying the aircraft to a removal location.

As such the target can be not only inhibited from remaining airborne but also brought under the control of the aircraft to facilitate a safe disposal.

So that the invention may be well understood, embodiments thereof will now be discussed with reference to the following figures, of which:

FIG. 1 shows a three-dimensional representation of an aircraft according to the invention;

FIG. 2a shows a plan view of a variant frame for use with aircraft;

FIG. 2b shows a plan view of an alternative frame for use with the aircraft;

FIG. 2c shows a plan view of a further alternative frame for use with the aircraft;

FIG. 3 shows a three-dimensional representation of a tubular member for use with the aircraft;

FIG. 4a shows a detail of the FIG. 3 member in a first condition; and

FIG. 4b shows a detail of the FIG. 3 member in a second condition.

Referring to FIG. 1 there is shown generally at 10 an aircraft device. The aircraft device 10 comprises an aircraft 100 which carries a payload 200.

The aircraft 100 is in the form of a light weight rotorcraft (e.g. under 25 kg) having a generally planar form and having four rotors 102 supported off a central housing 104, the rotors 102 being evenly distributed at the horizontal periphery of the aircraft 100.

The payload 200 comprises a trapeze mount 202, a frame 210, first lines 206 and second lines 208.

The mount 202 is attached at one end to the central housing 104 of the aircraft 100, and at the other end to the frame 210, and is configured such that in stable horizontal flight the frame 210 can hang in a generally horizontal plane.

The frame 210 comprises an outer loop member 212, which has the form of an annular ring in the present embodiment. It is, more specifically, the outer loop member 212 by which the mount 202 is attached to the frame 210.

The frame 210 further comprises an inner loop member 214, which also has the form of an annular ring, but is of diminished dimensions relative to the outer loop member 212 and is located concentrically therewith.

Connecting struts 216 attach the outer loop member 212 and the inner loop member 214 to one another.

Each of a first set of lines 208 is attached at one end to the outer ring 212, and hangs free at its other end. These outer lines 208 are spaced at regular intervals.

Each of a second set of lines 206 is attached at one end to the inner ring 214, and hangs free at its other end. These inner lines 206 are spaced at regular intervals.

The first set of lines 208 are thinner than the second set of lines 206. The first set of lines 208 have a diameter of between 0.1 mm to 2 mm, and more preferably between 0.4 mm and 0.7 mm. Accordingly the first, outer set of lines 208 are particularly suitable for tangling with propellers or rotors.

The second set of lines 206 have a diameter of between 3 mm and 8 mm, and more preferably between 4 mm and 6 mm. Accordingly, the second, inner set of lines 206 have the volumetric capacity to offer enhanced drone inhibiting provisions.

Both line types of line are of generally the same length.

Further embodiments of frames are shown in FIGS. 2a, b , and c.

FIG. 2a shows a frame having loop-style members, and here there are three concentric annular members 306, 304, and 302 (going from inside outwards). First type lines 208 may be hung from the outermost member 302, and second type lines 206 may be hung from the innermost members 304, 306.

FIG. 2b shows a frame 400 having linear members where the outer member comprises first and second separate members 406 and 402 which sit either side of an inner member 404. All three members are substantially parallel, of the same length, are coplanar, and are spaced apart at regular intervals. First type lines 208 may be hung from the outermost members 406, 402, and second type lines 206 may be hung from the innermost member 404.

FIG. 2c shows a frame 450 having linear members each of which is angled at its midpoint create a chevron form. Lines are arranged in a manner corresponding to the FIG. 2b embodiment and as such the frame 450 comprises a pair of outer members which are either side of a central member. The members are parallel and spaced at regular intervals.

In operation, an aircraft device 10 may be used to intercept a target rotorcraft by flying the aircraft device 10 over the target rotorcraft, such that the lines may interfere with the target rotorcraft.

A particular interference mechanism would involve the lines becoming wound around the rotors of the target rotorcraft. This would tend to inhibit the rotation of the rotors, and in turn the ability of the target rotorcraft to remain airborne. Moreover, this would tend to tether the aircraft device 10 to the target rotorcraft so as to enable the inhibited target rotorcraft to be dragged to a more favourable location for further neutralisation.

As a variant to the lines described above, an adhesive-expelling line 500 shown in FIG. 3 may be used as either or both of the first and second type of lines.

The line 500 comprises a flexible tubular member 502. The tubular member 502 provides a wall 508 and a bore 507. The wall 508 contains an adhesive fluid 505 within the bore 507.

Further, the wall 508 is provided with a plurality of slits 504. The plurality of slits 504 are arranged over the surface of the member 502 and extend through the thickness of the wall 508.

Each slit 504 is generally biased to remain closed as shown in FIG. 4a , particularly when the member 500 is in an equilibrium position (without any bending stress).

However, each slit is further configured, in certain circumstances, to facilitate the expression of the adhesive fluid 505. More particularly each slit is configured to, in certain circumstance, open up to provide a channel between the bore 507 and the outer surface 509 of the member 502.

To this end, as shown in FIG. 4b , each slit 504 is in the form of an elongate cut defining an axis S. Each axis S is arranged to be aligned with the circumference C of the member 502 such that axial bending which leads to tension along one side of the member 502 will tend to open up slits at the in-tension side, and allow adhesive to flow from the bore to the surface of the member 502.

Accordingly, when the adhesive-expressing line 500 is used in conjunction with the aircraft device 10 it offers a further mechanism whereby the line may interfere with a target rotorcraft and thereby tend to inhibit and control the motion of the target rotorcraft. Particularly the line 500 may, as it comes into contact with the target rotorcraft and wraps around it, tend to express adhesive 505 onto the surface 509 of the line 500.

This expressed adhesive 505 may inhibit the target rotorcraft by either:

transferring from the line 500 to the target rotorcraft and clogging up its mechanisms; or by helping to bond the line 500 to the target rotorcraft whereupon the aircraft 100 becomes physically connected to the target rotorcraft and can drag the target rotorcraft to another, more desirable (e.g. safer) location.

Whilst in the above example the lines are described as inhibiting a target rotorcraft, it is contemplated that the apparatuses and methods would be applicable to other target or hostile aircraft.

For example the lines discussed could be suitable for tangling with a propeller aircraft.

For example the adhesive-expressing line 500 operates in such a way that it may bond to any surface which tends to deform the line 500. Accordingly it may bond to target aircraft which lack rotors or propellers (e.g. jet engine driven aircraft).

In general, the airborne targets contemplated here are lightweight (e.g. under 25 kg) and unmanned. Such may be colloquially referred to as ‘drones’. 

What is claimed is:
 1. An aircraft for intercepting an airborne target, the aircraft comprising: a frame; a plurality of lines of a first type, each attached to the frame at a first end, and free at the other end; and a plurality of lines of a second, different, type, each attached to the frame at a first end, and free at the other end.
 2. The aircraft according to claim 1 wherein the frame comprises: an inner member; an outer member; and iterconnecting struts attaching the inner member to the outer member, the first type of lines are attached to the inner member, and the second type of lines are attached to the outer member.
 3. The aircraft according to claim 2 wherein the outer member is a loop member, and the inner member is a loop member located within the outer member.
 4. The aircraft according to claim 3 wherein each loop member has the form of an annular member.
 5. The aircraft according to claim 1 wherein the outer member is at least two linear members and the inner member is at least one linear member, the inner member being arranged between the at least two outer members.
 6. The aircraft according to claim 1, wherein the first type of lines are thinner than the second type of lines.
 7. The aircraft according to claim 1, wherein each of the second type of lines comprises: a flexible tubular member, having a wall and defining a bore, inner and outer diameters, and a circumference; and a fluid adhesive housed within the flexible tubular member, wherein the flexible tubular member is configured to express the fluid adhesive through the wall.
 8. The aircraft according to claim 7 wherein the flexible tubular member comprises: a plurality of slits through the wall, which slits are configured to remain generally closed, but on deformation of the flexible tubular member can open to permit expression of the adhesive.
 9. The aircraft according to claim 8 wherein the slits follow a portion of the circumference of the tubular member.
 10. The aircraft according to claim 7 wherein the wall of the tubular member is in the form of a porous matrix such that the fluid adhesive may be urged to the outer diameter of the tubular member.
 11. The aircraft according to claim 1, wherein the aircraft is a rotorcraft.
 12. The aircraft according to claim 1, wherein the aircraft has a mass of 25 kg or less.
 13. The aircraft according to claim 1, wherein the aircraft is remotely or autonomously piloted.
 14. A method of intercepting an airborne target comprising: providing an aircraft comprising: a frame; a plurality of lines of a first type, each attached to the frame; and a plurality of lines of a second type, each attached to the frame, and flying the aircraft over and across the airborne target such that the lines may attach to the airborne target.
 15. The method according to claim 14 further comprising, once the lines have attached the aircraft to the airborne target, removing the airborne target by flying the aircraft to a removal location. 